Optical recording media have been widespread generally because of their superiority such as high recording capacity and non-contact write/read system. Recordable optical disks such as WORMs, CD-Rs, and DVD-Rs record information by irradiating a very small area of the optical recording layer with a focused laser beam to change the properties of the irradiated area and reproduce the recorded information making use of the difference in reflected light quantity between the recorded area and the non-recorded area.
Wavelengths of semiconductor lasers used in writing and reading information on the currently available optical disks of the type described are in the ranges of 750 to 830 nm for CD-Rs and of 620 to 690 nm for DVD-Rs. In pursuit of a further increased capacity, optical disks using shorter wavelength lasers have been under study. For example, those using a write wavelength of 380 to 420 nm have been studied.
Various kinds of compounds are used to form an optical recording layer of optical recording media for short wavelength lasers. For example, Patent Document 1 reports azo compounds; Patent Document 2, porphyrin compounds; Patent Document 3, triazole compound metal complexes. These compounds, however, are not always good for use as an optical recording material forming an optical recording layer in view of their absorption wavelength characteristics.
On the other hand, compounds that absorb light of 300 to 390 nm wavelength are used as a UV absorber of an optical filter for application to image display devices including liquid crystal displays (LCDs), plasma display panels (PDPs), electroluminescence displays (ELDs), cathode ray tubes (CRTs), fluorescent display tubes, and field emission displays (FEDs).
For example, Patent Document 4 discloses a filter for organic electroluminescence (EL) displays that contains a UV absorber and blocks light of 200 to 410 nm wavelength. However, the UV absorber used in the filter for organic EL displays is not always suited for use as a UV absorber of optical filters in view of its absorption wavelength characteristic.    Patent Document 1: JP 2004-209771A    Patent Document 2: JP 2004-58365A    Patent Document 3: JP 2004-174838A    Patent Document 4: JP 2004-102223A